The present invention is directed generally to illumination arrangements in electronic devices, such as wristwatches (by example and not by limitation), and, in particular, to an improved illumination arrangement for illuminating elements in the device, such as one or more indicator hands, such as the hour and minute hand, by way of example.
The technology for illuminating the hands of an electronic device is quite varied. Some of the more readily accessible designs can be found in U.S. Pat. No. 3,490,226 (clock); U.S. Pat. No. 5,546,888 (gauges); U.S. Pat. Nos. 5,697,322; 5,751,622 and Published application No. 2003/0112712. Most of these technologies illuminate the hands from the bottom (i.e. from the dial side of the device).
The use of ultraviolet light to illuminate the hands of a timepiece is also known. For example, U.S. Pat. No. 4,561,042 and Published application No. WO 2004/034153 describe the use of a light emitting element mounted on the side of the case that in effect merely “blasts” ultraviolet lightwaves towards the hands of the timepiece to irradiate the surfaces of the hands causing them to emit visible light. However, both of these ideas are believed to be less than desirable due to their inability of most efficiently directing the light into the hands of the device.
Although the idea of providing a lightsource above the dial (as opposed to below or on the side) is known from U.S. Pat. No. 6,299,321, this patent also lacks any description or suggestion of most efficiently directing the light downwardly into the hands, as it too describes the mere idea of “blasting” light towards the hands.
There is also a need to overcome the perceived deficiencies in merely using an LED that emits light in the visible spectrum, as such devices do not provide for a satisfactory illumination of the hands, and they also use a considerable amount of energy, relatively speaking.
Accordingly, there is a need to provide an illumination arrangement for an electronic device, such as a wristwatch by example and not limitation, that provides for a more efficient illumination of the indicator hands using UV lightwaves. It is believed that the foregoing is best achieved by positioning such a UV light emitting element directly above the one or more indicator hands in the device and providing the one or more hands with an angled surface to more efficiently allow the lightwaves to propagate therethrough.